Among my father's tools I found a folding wooden rule by Lufkin marked Doyle Log Scale. The markings don't add up to board feet but then I may be reading it wrong. If anyone can help me, I would appreciate it.

-Gerald Stump

Log buyers use the Doyle log rule. It tells how many board feet of usable lumber is in a log of given diameter and length. It assumes a saw with a 1/4-inch kerf and a log with no defects. A band saw mill will yield 5-10 percent more. The log diameter is measured on the small end inside the bark. As an example, an 8-foot log, 12 inches in diameter will yield 32 board feet. This should allow you to figure out how to read the scale.